1. Field of the Invention
The invention relates to a telescopic shock absorber, particularly to a shock absorber operating by compression, or shock absorption through the use of air cushions, and is primarily applicable to motor vehicles having parts which need to be cushioned relative to one another. The shock absorber is of the type wherein a cylinder-shaped tube is attached to one part of the vehicle, the tube containing a tight, sliding shock damping assembly, and being connected to another part of the vehicle by a rod, the assembly exerting a braking action between the relative parts.
2. Description of the Prior Art
For the purpose of producing shock absorption particularly applicable to motor vehicles, several approaches are known besides shock absorption through liquid media. The designs are intended to overcome the disadvantages inherent in shock absorbers operating on liquid media. In an existing design, for instance, the piston is shaped as an expanding piston with a conical part meshing with a corresponding, sliding, hollow-conical part of the piston, with their bases facing forward.
Another design provides an arrangement of sectors that act as braking elements upon a piston shaped as a truncated cone, its base inserted to face forward, with the sectors held under pressure provided by springs supported by the rod.
The rod is pushed against the truncated cone as the sectors slide towards it. All these proposals are more or less complicated, wasteful, and comparatively expensive to manufacture. Their operation is based primarily on friction which in its operation will generate heat that may have a detrimental effect on the component parts of the shock absorber. Also, the desirable progressiveness of the shock absorption effect is achieved only partially. Reference is also made to Freyler, U.S. Pat. No. 3,713,516 which illustrates a prior art telescopic shock absorber wherein the plunger inside the cylinder is split along an oblique separation line.